Solar simulators are used to test solar panel modules. A viable simulator must include a light source whose output matches the solar spectrum. Specular spatial, irradiance spatial, and temporal uniformity are also requirements.
An example of a compact solar simulator is the “Spi-Sun Simulator™ SLP” offered by the applicant hereof. Other solar simulators are discussed, for example, in U.S. Pat. Nos. 7,514,931 and 7,528,615 incorporated herein by this reference. Compact solar simulators typically have a lamp or lamps fairly close to the target surface as opposed to some distance away as is the case with projection simulators.
In the prior art, a mask was sometimes used to control the intensity distribution of light from the source at the target surface upon which the solar panel module rests or over which the solar panel module is positioned. In one example, the mask was placed on filter panels themselves residing on an acrylic surface between the source(s) and the target surface.
Creating a mask for each production unit, installing it, and testing it is a very time consuming and expensive procedure. Creating a mask can also be a procedure which is difficult to replicate. A mask can also noticeably reduce the overall intensity at the test plane requiring that additional energy be put into the source lamp(s).